Polymerization catalysts and methods

ABSTRACT

A catalyst and method in which the catalyst is active with a cocatalyst in the polymerization and copolymerization of 1-olefins and is prepared by reacting together one or more of a specific class of organic silicon compounds, a porous support or a silicon compound treated porous support, a Group IIA organometallic compound, and a Group IVB, VB transition metal compound or mixture thereof.

BACKGROUND OF THE INVENTION

The polymerization and copolymerization of 1-olefins rapidly andeconomically with a catalyst was primarily initiated by K. Ziegler whodeveloped two component catalyst systems based on compounds of the GroupIV-VIB metals of the periodic table with an organometallic compound ofGroups I-IIIA of the periodic table. These catalysts efficientlypromoted the polymerization and copolymerization of olefins. Since thisdiscovery, numerous catalysts have been developed as improvements overthe original Ziegler catalysts.

Although these later developments based on the original work by Zieglerproduced in many instances superior catalysts, none have the improvedproperties and characteristics achieved with the catalysts of thepresent invention.

The catalysts of this invention are defined as follows:

A solid catalyst for use with an organometallic cocatalyst in thepolymerization and copolymerization of 1-olefins, prepared by reacting:

(A) a support having surface hydroxyl groups and comprising

(1) silica, alumina or silica-alumina or mixtures of these, or

(2) an organosilane treated support of (A-1) or mixtures of these;

(B) an organosilicon compound of the formula (R₃ Si)₂ NH, where R is ahydrocarbyl group selected from C₁ -C₂₀ alkyls, aryls, alkaryls oraralkyls or mixtures of these;

(C) a Group IIA organometallic compound or a complex of said Group IIAcompound with a Group IIIA organometallic compound; and

(D) a transition metal compound of a Group IVB, Group VB or mixtures ofthese metals; or

(C') the Group IIA organometallic compound or complex of step (C) isreacted with the product of step (A-2) prior to the reaction of step(B).

The catalysts of this invention have very high activity and producepolymers which do not require a catalyst removal step. The catalysts ofthe invention are free flowing and produce polymers with good particlenature. The polymers made by using the new catalysts described hereinhave narrower molecular weight distribution and lower elasticity thanpolymers produced by prior art catalysts. The specific organic siliconcompounds of this invention interact with or on the catalyst activesites and modify the catalyst's electronic structure resulting in thefollowing unusual polymer properties. Polymers with lower elasticity andnarrower molecular weight distribution are prepared and can be used toproduce high strength objects such as blown films. This is highlyimportant especially in the production of blown films from theethylene-α-olefin copolymers currently manufactured under the commonlyused term, linear low density polyethylene (LLDPE).

The catalysts also can be used to produce polymers with higher meltindex than prior art catalysts. Polymers with high melt index and narrowmolecular weight distribution permit the production of exceptionallytough and stiff products with faster production cycle.

SUMMARY OF THE INVENTION

This invention relates to improved supported catalysts and theirpreparation, and methods for the polymerization and copolymerization ofolefins. The catalysts are made by combining in the presence or absenceof an inert liquid media, a porous support or a silicon compound treatedporous support, any of a specific class of organic silicon compounds, aGroup IIA organometallic compound uncomplexed or complexed with a GroupIIIA organometallic compound and a Group IVB, VB, or both transitionmetal compound. The solid catalyst obtained is activated with analkylaluminum cocatalyst.

The porous support is either silica, alumina or both or silicon compoundtreated silica, alumina or both. The silicas or aluminas that aresuitable for this invention may contain minor amounts of zirconia,magnesia or titania. Reaction of the support with an organic siliconcompound of the formula (R₃ Si)₂ NH, where R is a hydrocarbyl group isan important variation in producing the catalysts of this invention.After reaction with the silicon compound, a Group IIA organometalliccompound is added followed by a Group IVB, VB or mixture thereoftransition metal compound. The catalysts are suitable for gas phase,particle form, solution form, or high pressure low density processes.The polymers made by this catalyst do not need a post reaction step toremove the catalyst residues, although such may be done if desired. In aparticle form process, the polymers are particulate in nature and do notshow fouling tendencies compared to prior art catalysts.

The catalysts of this invention are highly active and are suitable forpolymerization of ethylene alone, and the copolymerization of ethylenewith 1-olefins of 3-8 carbon atoms or mixtures to form polymers of low,medium and high densities. These catalysts are especially effective inthe production of high and low density polyethylene having a narrowmolecular weight distribution and high melt index.

The melt index of the polyethylene produced by the catalysts of thisinvention can be controlled by methods known to the art such asincreasing the temperature of polymerization or by the addition ofhydrogen.

DESCRIPTION OF PREFERRED EMBODIMENTS

The catalysts of this invention are prepared in two ways which differ inthe pretreatment of the porous support. In one case, the support is notdried or calcined but is treated with sufficient organic siliconcompound having functional groups to react with all hydroxyl groupspresent on the support. Following this all unreacted organic siliconcompound and by-products are removed to give a free flowing siliconcompound treated porous support.

In a second case, the support is dried or calcined. In this second case,an excess of a specific class of organic silicon compound over thatrequired to react with the hydroxyl groups must be present as a part ofthe catalyst. Thus, a key critical feature is the presence of excessspecific organic silicon compound added to an already completely siliconcompound treated porous support or calcined porous support prior to orafter the addition of a Group IIA organometallic compound followed bythe Group IVB and/or VB transition metal compound.

The catalyst of this invention may be prepared in an inert liquid media,preferably hydrocarbons, straight or branched chain C₃ to C₈ aliphaticliquid hydrocarbons, including liquid propane, liquid isobutane, andmixed branched hydrocarbons such as Isopar H.

The porous support is selected from the group consisting of silica oralumina or mixtures thereof. It may contain minor amounts of zirconia,magnesia or titania such as a zirconia-silica cogel or azirconia-titania-silica tergel. The preferred support is silica. Thesupport is dried or calcined at temperatures in the range of from about200° to 1000° C. Alternatively, the support is not dried and is treatedwith an organic silicon compound that reacts with the support hydroxylgroups. The organic silicon compounds used may have at least one of thefollowing formulae:

    (R.sub.3 Si).sub.2 NH

    RnSiX.sub.4-n

where R is a hydrocarbyl group having from C₁ to C₂₀ carbon atomsincluding alkyls, aryls, alkaryls, aralkyls, etc. and may be the same ordifferent; X is halogen; n =1, 2 or 3. Examples aretrimethylchlorosilane, hexamethyldisilazane, etc. The reaction with theorganic silicon compound can be done in any convenient way, i.e., insolution, direct reaction with the support or under vapor phaseconditions, etc. The excess organic silicon compound and reactionproduct are removed after reaction with the support.

The dried, calcined, or silicon compound treated support is thencontacted with the specific organic silicon compound having thefollowing structural formula:

    (R.sub.3 Si).sub.2 NH

where R is a hydrocarbyl group selected from C₁ to C₂₀ alkyls, aryls,alkaryls, aralkyls, etc. The R groups may be identical or different.Examples are hexamethyldisilazane, hexaphenyldisilazane,trimethyltriethyldisilazane, etc.

The addition of the specific organic silicon compound to the support orcatalyst under preparation can be done in any convenient way, i.e., inslurry or in a fluidized or agitated state, said specific organicsilicon compound being introduced as liquid, vapor or solution. It isadded prior to or after the addition of the Group IIA organometalliccompound. The quantity added is from 0.2 to 2.0 molar equivalents to theGroup IIA organometallic compound. The preferred range is 0.5 to 1.5molar equivalents of the specific organic silicon compound to the GroupIIA organometallic compound.

The Group IIA organometallic compounds are preferably the hydrocarbylderivatives of magnesium and calcium or their complexes with Group IIIAmetal compounds, especially aluminum compounds such as alkyl aluminumcompounds. Especially suitable are those of the general formula MgR₂.nAlR₃ where R is a hydrocarbyl group as defined above and n is about0-2. Examples are n-butylethylmagnesium, 0.5di-n-butylmagnesium-triethylaluminum complex, and 6.1di-n-butylmagnesium-triethylaluminum complex (Texas Alkyls'Magala 6.1E).

The concentration of the Group IIA organometallic compound may be equalto, greater than, or less than the porous supports original surfacehydroxyl concentration and the molar ratio of magnesium compound tosurface hydroxyl is about 0.1-5.

The Group IVB and/or VB transition metal compounds are halides oralkoxyhalides of these metals, with the preferred metal being titanium,zirconium or vanadium. The especially preferred titanium compounds maybe selected from the following formulae:

    TiX.sub.4

    TiX.sub.m (OR).sub.4-m

in which X is halide, R is hydrocarbyl such as alkyl, aryl, etc., havingfrom 1 to 20 carbon atoms and m is 1, 2 or 3. Examples are titaniumtetrachloride, n-butoxytitanium trichloride, etc. The quantity of thetransition metal compound is preferably in about a one to one molarratio with the Group IIA organometallic compound. Lower or higher ratioscan be used.

In many cases the activity of the reaction product is greatly increasedby the addition of an organometallic cocatalyst, the metal preferablybeing aluminum, either prior to polymerization or simultaneously withthe introduction of the catalyst to the polymerization vessel. It ispreferred to use an alkylaluminum compound as a cocatalyst. The ratio ofaluminum to transition metal may range from up to about 500 to 1,preferably about 1-50 to 1. Various alkylaluminum compounds function ascocatalysts, the preferred compounds depending upon the polymerizationconditions. Typically, suitable compounds are triethylaluminum,trioctylaluminum, triisobutylaluminum, diisobutylaluminum hydride,tri(2-methyl pentyl)aluminum, diethylaluminum chloride, ethylaluminumdichloride, diethylaluminum ethoxide, diethylaluminum trimethylsiloxide,etc.

The catalysts of this invention may be used as dry solids, slurries,dispersions in hydrocarbon liquids, solutions or colloidal suspensionsin hydrocarbon liquids.

Preparation of a catalyst of this invention is remarkably simple. Allthat is required is to mix the ingredients in a single vessel, in thepreferred concentrations and if desired in the presence of an inertliquid media. The inert liquid media, if employed, is evaporated whileheating to a final drying temperature of about 90°-130° C. The dry freeflowing catalyst is transferred to a dry inert atmosphere filledcontainer where it is stored for use. An in situ silanation of a driedor calcined support with excess specific organic silicon compound is oneof the important features of the preparation. Another important featureis the presence of excess specific organic silicon compound added to apresilanated, preferably completely silanated, porous support prior toaddition of the remaining components of the catalyst. In this case, nodrying or calcination of the support prior to treatment with an organicsilicon compound is necessary, since the support is alreadysubstantially free of water. However, the excess organic siliconcompound plus by-products of the treatment must be removed prior to theaddition of the remaining components of the catalyst.

To summarize, therefore, the catalyst of this invention is prepared by(1) reacting an excess of a specific organosilicon compound with aporous support essentially free of surface absorbed water, (2) reactingthe product of (1) with a Group IIA organometallic compound or complexthereof with a Group IIIA organometallic compound and (3) reacting theproduct of (2) with a halide, oxyhalide, or alkoxyhalide of a metal ofGroup IVB or Group VB or mixtures of these. The solid catalyst productof (3) is used with a cocatalyst prior to and/or during thepolymerization reaction.

The catalyst of this invention is also prepared by (1) reacting a poroussupport having surface absorbed water with excess organosiliconcompound, (2) removing excess silicon compound and by-products from (1),(3) adding a specific organic silicon compound prior to or after mixingwith a (4) Group IIA organometallic compound or complex with a GroupIIIA organometallic compound and (5) reacting with a halide, oxyhalide,or alkoxyhalide of a metal of Group IVB or VB or mixtures of these. Thesolid catalyst product of (5) is used with an alkyl or arylaluminumcompound cocatalyst prior to and/or during the polymerization reaction.

Efficient mixing of catalyst ingredients is done in a closed vessel,under pressure or at atmospheric pressure, under an inert atmospheresuch as nitrogen, at temperatures from about 0° C. to 150° C. and withminimal hold periods between component additions. The presence of aninert liquid media aids in the mixing. After evaporation of the inertmedia, the dry product reaches a temperature between about 70° C. and150° C. and is held for about one hour.

The sequence of mixing the components of the catalyst may be any of thefollowing:

1. Silanated support or dried support followed by excess of the siliconcompound, magnesium compound, and titanium compound.

2. Silanated support followed by the magnesium compound, siliconcompound, and titanium compound.

When using the catalysts of this invention, at least one α-olefin of theformula RCH=CH₂, wherein R is hydrogen or a straight chain or branchedalkyl group having from 1 to 10, preferably 1-8, carbon atoms, ispolymerized. Examples of such olefins are ethylene, propylene, butene-1,hexene-1, 4-methyl pentene-1, and octene-1. Ethylene is polymerizedalone or with mixtures of one or more of the above olefins.

The polymerization may be carried out in suspension, in the gas phase,or under solution conditions, continuously or discontinuously, attemperatures from about 20°-300° C., preferably from 60°-110° C., andunder pressures preferably from about 10030,000 psi.

The melt index of the polymers produced can be controlled by methodsknown to the art such as increasing the temperature of polymerization orby addition of hydrogen.

The polymers made by this invention show narrower molecular weightdistribution, higher melt index, lower elasticity and high and lowdensities desirable for the production of high performance polymergrades.

The catalysts are useful for producing polymers of 1-olefins of 2-8carbon atoms and copolymers of these with 1-olefins of 2-20 carbonatoms.

EXAMPLES

Comparative Example 1 and invention Examples 2 to 6 inclusive in Table Ishow that the catalysts of this invention are active and exhibit greaterproductivity, especially under low density copolymerization conditions,than supported catalysts not containing a silicon compound according tothis invention, as shown in Example 1.

EXAMPLE 1 Table I (comparative)

A catalyst was prepared from Davison Chemical Company Grade 952 silica.The reactions were conducted in a dry, N₂ purged flask immersed in anice water bath. First 3.3 g of the silica was added and the silica wasstirred for thirty minutes at the low temperature. Then 20.8 ml of a(Bu₂ Mg)₆. 5 Et₃ Al solution in heptane (10 wt.%) was added by syringe(1.46 g of complex). The mixture was stirred for 30 min. then 1.13 ml(1.92 g) of titanium tetrachloride was added. After an additional 30min. at 0° C., the flask was placed in a bath at 90° C. and the solventwas evaporated under nitrogen flow. A portion of the catalyst was testedin a pressure vessel using isobutane diluent at a total pressure of 550psig at 221° F. with a hydrogen partial pressure of 50 psig. TIBAL wasadded to give 9.2 mmoles/g of solid catalyst. The reactivity was foundto be 2445 g/g cat/hr.

EXAMPLE 2 Table I (invention)

A catalyst was prepared by mixing under N₂, 1.5 g Davison Grade 952silica, previously dried at 300° C., with 30 cc n-heptane and 0.39 cc(20 wt.% of the silica) of hexamethyldisilazane (in-situ silanation).This mixture was heated to 90° C. and stirred for one hour and thencooled. An 8.9 wt.% solution of (Bu₂ Mg)₆.1 Et₃ Al in n-heptane, 4.46cc, was then added. After stirring this mixture for 0.5 hr., 0.22 cc ofTiCl₁₄ was added followed by stirring for an additional 0.5 hr. Removalof the n-heptane diluent with N₂ at 90° C. resulted in a dry brownfreeflowing catalyst powder. A portion of the catalyst was tested undersimilar conditions as described in Example 1, Table I, but with 8.5mmoles/g catalyst of triisobutylaluminum as cocatalyst and at 215° F.The reactivity was found to be 3893 g/g cat/hr.

EXAMPLE 3 Table I (invention)

Hexamethyldisilazane treated Davison Grade 952 silica, 1.6 g, was driedin N₂ for one hour at 110° C. To the dry silane treated support wasadded 20 cc of n-heptane and 0.14 cc additional hexamethyldisilazane (7wt.% of the support). This mixture was stirred for 10 min. followed bythe addition of 4.75 cc of 8.9 wt.% (Bu₂ Mg)₆.1 Et₃ Al in n-heptane,stirring for an additional 10 min., and the addition of 0.22 cc titaniumtetrachloride. The mixture was dried at 100° C. with a N₂ purge to yielda black free-flowing catalyst. Reactivity under conditions set forth inExample 2, Table I, was 2464 g/g cat/hr.

EXAMPLE 4 Table I (invention)

The catalyst of this example was prepared like the catalyst of Example2, Table I, except for the concentration of ingredients. Thus, 1.5 g ofDavison Grade 952 silica, dried at 300° C. in N₂, was mixed with 20 ccn-heptane and 0.39 cc of hexamethyldisilazane (in-situ silanation). Themixture was refluxed at 90° C. for one hour and then cooled. A solutionof 8.9 wt.% (Bu₂ Mg)₆.1 Et₃ Al in n-heptane, 6.2 cc, was added and themixture stirred 0.5 hr. Addition of 0.29 cc of titanium tetrachlorideproduced a dark brown product which was then freed of n-heptane by N₂purge at 100° C. A free-flowing dark brown catalyst was obtained. Aportion of this catalyst was tested under low-density copolymerizationconditions in isobutane diluent, with 8.5 mmoles/g catalyst oftriisobutylaluminum cocatalyst, at 160° F., with a partial pressure of50 psig hydrogen, with 22 mol % butene-1 as comonomer and with ethylenefed on demand at 350 psig total reaction pressure. Exceptionally highreactivity of 4797 g/g cat/hr. was reached giving an ethylene- butene-1copolymer with density 0.922 g/cc.

EXAMPLE 5 Table I (invention)

This catalyst is similar to that of Example 3, Table I, in that excesshexamethyldisilazane was added to an already silanated silica followedby the magnesium complex and the titanium compound. However, thecatalyst was prepared on a larger scale by combining under N₂ in 1000 ccn-hexane, 200 g of the hexamethyldisilazane treated Davison Grade 952silica, dried one hour at 100° C., with 18 cc additionalhexamethyldisilazane (7 wt.% of the silanated silica support), 703 cc ofa 10 wt.% solution of (Bu₂ Mg)₇.1 Et₃ Al in n-heptane and with 38.6 cctitanium tetrachloride. The mixture was stirred for one hour and thendried at 110° C. with N₂ purge for 20 hr. A black free-flowing catalystremains. As in Example 4, Table I, testing was under low-densitycopolymerization conditions. Again, exceptionally high reactivity wasreached at 5763 g/g cat/hr. The copolymer produced had a density of0.916 g/cc indicating good incorporation of butene-1.

EXAMPLE 6 Table I (invention)

This catalyst is similar to the catalyst of Example 2, Table I, exceptthat it was prepared on a one pound scale with 700° F. calcined DavisonGrade 952 silica, in a closed vessel, with no hold periods or ventingbetween component additions and in isobutane diluent. Thus, 455 g of700° F. Davison Grade 952 silica was charged to a steel vessel under N₂and the vessel sealed. About 4800 cc of isobutane was charged underpressure and the mixture agitated for 5 min. Heat was applied and theentire vessel vented to remove isobutane and all traces of oxygen fromthe support. The vessel was again closed and 48 cc ofhexamethyldisilazane and 1400 cc isobutane was added at <150° F. withagitation followed immediately with 1180 cc of a 10.6 wt.% solution of(Bu₂ Mg)₇.5 Et₃ Al in n-hexane and 62 cc titanium tetrachloride. Theremainder of the vessel was filled with 700 cc additional isobutane andthe contents agitated at 195° F. for one hour. Venting with a N₂ purgewhile maintaining the temperature at about 195° F. provided a dryfree-flowing brown catalyst which was transferred to a storage vesselunder N₂.

This catalyst reached an exceptionally high productivity level of 16,500g copolymer/g catalyst under low density particle form copolymerizationconditions in isobutane at 168° F., 600 psig total pressure, 0.22 mol %hydrogen, 4 wt.% ethylene, 13.3 mol % butene-1 and withtriisobutylaluminum at 3.7 mmoles/g catalyst. The copolymer obtained hada density of 0.924 g/cc.

Invention Examples 7-10 of Table II show that narrow molecular weightdistribution ethylene homopolymers are produced at variousconcentrations of the silicon compound when used by the in situsilanation catalyst preparation invention method. Example 11, Table II,shows that the variation of the invention where excess silicon compoundis added to an already silanated support followed by the magnesium andtitanium compounds, also gives rise to resins with narrow molecularweight distribution. Example 12, Table II, shows that much lowercatalyst activity results when a catalyst similar to the catalystdescribed in invention Example 8 is prepared without removing thephysisorbed water from the support by calcination. Examples 13 and 14 ofTable II demonstrate yet another variation of the invention catalystwhere the magnesium compound is added first to the already silanatedsupport followed by additional silicon compound and the titaniumcompound. These catalysts showed good activity in the production ofhexene-1 copolymers. Comparative Example 15, Table II, shows that theabsence of excess silicon compound gives rise to a catalyst whichproduces a copolymer, under similar synthesis conditions, with muchlower melt index and higher HLMI/MI ratio.

EXAMPLE 7 Table II (invention)

A catalyst was prepared by mixing under N₂, 1.3 g of 400° F. calcinedDavison Grade 952 silica with 20 cc n-hexane and 0.17 cchexamethyldisilazane (0.62 mmoles/g support). After one hour, 3.86 cc ofan 8.9 wt.% solution of (Bu₂ MG)₆.1 Et₃ Al in n-heptane was addedfollowed in 0.5 hr. by 0.18 cc of titanium tetrachloride. The mixturewas dried with N₂ purging at 90° C. to give a brown free-flowingcatalyst. A portion of the catalyst was used in ethylene polymerizationat 215° F. using triisobutylaluminum as a cocatalyst and a 50 psigpartial pressure of hydrogen. The reactivity of the catalyst was 2156g/g cat/hr. and the resin had a low HLMI/MI ratio of 29.6 indicatingnarrow molecular weight distribution.

EXAMPLE 8 Table II (invention)

A catalyst similar to the above example was prepared except that theconcentration of hexamethyldisilazane was increased to 1.22 mmoles/gsupport. Ethylene polymerization in the presence of triisobutylaluminumshowed a reactivity of 2266 g/g cat/hr. A low value for the HLMI/MIratio (24.3) again indicated a narrow molecular weight distribution.

EXAMPLE 9 Table II (invention)

This catalyst is similar to Example 7, Table II, except that theconcentration of hexamethyldisilazane was further increased to 1.83mmoles/g support. Reactivity of the catalyst under similar conditionswas 1002 g/g cat/hr. The HLMI/MI ratio was 26.2.

EXAMPLE 10 Table II (invention)

The final catalyst of this series was prepared with 2.47 mmoles/ghexamethyldisilazane. Reactivity was 1052 g/g cat/hr. Resin HLMI/MIratio was 21.8 again indicative of narrow molecular weight distribution.

EXAMPLE 11 Table II (invention)

This catalyst is identical to that described in Example 3, Table I.Resin produced by this catalyst under homopolymer polymerizationconditions has a low HLMI/MI ratio of 28.1 a value within the range ofvalues determined on similar resins produced by the in-situ silanationcatalyst preparation method.

EXAMPLE 12 Table II (comparative)

Much lower catalyst activity results when a catalyst similar to thecatalyst described in invention Example 8, Table II, is prepared withoutremoving the physisorbed water from the silica by calcination. Thus, 450g of raw Davison Grade 952 silica was charged under N₂ to a steel vesseland sealed. All trace of air was then removed by alternativelypressurizing the vessel with N₂ and venting, five times. At 25° C., 130cc of hexamethyldisilazane and 1500 cc of isobutane were charged, underpressure sufficient to liquify the isobutane, followed by agitation ofthe mixture for one hour. The reaction mixture was vented and thenresealed. With agitation, 1180 cc of 10.6 wt. % (Bu₂ Mg)₇.5 Et₃ Al inn-hexane was added together with 1500 cc isobutane. After agitation for0.25 hour, 62 cc of titanium tetrachloride and 1500 cc additionalisobutane was pressurized into the vessel. This mixture was agitated forone hour at 212° F. followed by venting and drying with N.sub. 2purging. The nearly white catalyst was dropped from the vessel into a N₂filled dry container. With triisobutylaluminum as cocatalyst, thiscatalyst showed poor activity at 581 g/g cat/hr.

EXAMPLE 13 Table II (invention)

Under N₂, 1.7 g of dry hexamethyldisilazane treated Davison Grade 952silica was mixed with 20 cc n-hexane and a 6.4 cc solution of 9 wt. %(Bu₂ Mg)₇.1 Et₃ Al in n-heptane. After 0.5 hour, 0.66 cc ofhexamethyldisilazane was added followed by heating of the mixture at 90°C. for 0.5 hour and cooling. A solution of 0.35 cc titaniumtetrachloride in 20 cc n-hexane was added followed by drying of themixture at 90° C. with N₂ purge. A brown-green free-flowing powderedcatalyst results. The copolymerization of ethylene with hexene-1 in thepresence of hydrogen at 130° F., 265 psi and with triisobutylaluminum ascocatalyst gave a copolymer with density 0.930 g/cc, MI 4.7, and HLMI/MIratio of 32. Activity was 2508 g/g cat/hr.

EXAMPLE 14 Table II (invention)

This catalyst was prepared as in Example 13, Table II, but with lesssilicon compound. Testing under similar copolymerization conditions gavea copolymer with 0.930 g/cc density, 2.9 MI, and HLMI/MI ratio of 29.4.Activity was 2519 g/g cat/hr.

EXAMPLE 15 Table II (comparative)

Under N₂, 1.7 g of dry hexamethyldisilazane treated Davison Grade 952silica was mixed with 20 cc n-hexane and a solution of 6.4 cc 90 wt. %(Bu₂ Mg)₇.1 Et₃ Al in n-heptane. This mixture was stirred 0.5 hourfollowed by the addition of 0.35 cc titanium tetrachloride. The productwas dried at 100° C. with N₂ purging. Testing under similar conditionsgave a copolymer with 0.930 g/cc density, but with much lower MI and amuch higher HLMI/MI ratio of 60.5.

Examples 16 and 17 of Table III compare, under particle formcopolymerization conditions, a catalyst of this invention prepared bythe in situ silanation method and a catalyst prepared from a completelysilanated, but without excess silicon compound. Results show that thecatalyst of this invention gave low-density resins with narrowermolecular weight distribution (lower R_(d)) and higher notched Elmendorftear strength (MD tear).

EXAMPLE 16 Table III (comparative)

450 g of hexamethyldisilazane treated Davison Grade 952 silica was driedat 110° C. for one hour and then charged under N₂ to a steel vessel andsealed. All traces of air were then removed by alternativelypressurizing the vessel with N₂ and venting, five times. With agitation,1180 cc of 10.6 wt. % (Bu₂ Mg)₇.5 Et₃ Al in n-hexane was added togetherwith 1500 cc isobutane. After mixing for one hour, 62 cc of titaniumtetrachloride was added along with 1500 cc additional isobutane. Thismixture was mixed for one hour at about 200° F. followed by venting anddrying with N₂ purging. The brown product was transferred under N₂ to aN₂ filled vessel. With triisobutylaluminum as cocatalyst, this catalystshowed a productivity of 8300 g/g catalyst under particle formcopolymerization conditions in isobutane diluent with hydrogen,ethylene, and butene-1 at 168° F. A copolymer with MI 0.8, R_(d) 3.7,density 0.920 showed a notched Elmendorf machine direction tear strengthof only 130 grams.

EXAMPLE 17 Table III (invention)

Davison Grade 952 silica was calcined at 1100° F. for 2 hr. 450 g wascharged under N₂ to a steel vessel along with 4800 cc of isobutane. Thismixture was agitated for 5 min. followed by venting to remove theisobutane along with all traces of air. The vent was closed and 52 cc ofhexamethyldisilazane was added under pressure with 1450 cc of isobutane(in situ silanation). While agitating, 1202 cc of 10 wt. % (Bu₂ Mg)₆.5Et₃ Al in n-heptane followed immediately by 62 cc titanium tetrachloridewas added along with 1700 cc additional isobutane. Heat was applied to195° F. where it was held for one hour. At the end of one hour, thevessel was vented under N₂ purge until the product was dry. The brownfree-flowing catalyst was transferred to a N₂ filled flask. A portion ofthe catalyst was tested, with triisobutylaluminum as cocatalyst, underconditions similar to that described in Example 16, Table III. Acopolymer with MI 0.7, lower R_(d) 2.9, and a density of 0.919 g/cc wasobtained at an exceptionally high productivity level of 12,500 g/gcat/hr. The notched Elmendorf machine direction tear strength was morethan doubled at 274 grams.

Examples 18 and 19 of Table III compare, under particle formterpolymerization conditions, a catalyst of this invention and acatalyst prepared without the specific organic silicon compound. Resultsshow that the catalyst of the invention gave low density1-butene-1-hexene terpolymer with narrower molecular weight distribution(lower R_(d)) and higher melt index.

EXAMPLE 18 Table III (invention)

450 g of hexamethyldisilazane treated Davison Grade 952 silica was driedat 110° C. for one hour and then charged under N₂ to a steel vessel andsealed. All traces of air were then removed by charging the vessel with4800 cc of isobutane, agitating the mixture, heating and then ventingwith N₂ purge. The vent is then closed and 2402 cc of 10 wt. % (Bu₂Mg)₆.5 Et₃ Al in n-heptane was added with 300 cc of isobutane. Themixture was agitated at ≦150° F. for one hour. Hexamethyldisilazane, 165cc, was then added along with 300 cc isobutane. After agitating for onehour, 124 cc of titanium tetrachloride was added with 400 cc additionalisobutane. While agitating, the mixture was heated to 205° F. and heldat that temperature for one hour. While maintaining the temperature asclose as possible at 205° F., the vessel was vented to dry the catalyst.The dark brown free flowing product was transferred under N₂ to a N₂filled vessel. With triisobutylaluminum as cocatalyst, this catalystunder particle form terpolymerization conditions in isobutane diluentwith hydrogen, ethylene, 1-butene and 1-hexene at 165° F., produced aterpolymer resin with MI 1.0, R_(d) 3.1 and density 0.918.

EXAMPLE 19 Table III (comparative)

This catalyst was prepared exactly as described in Example 16, TableIII. An ethylene, 1-butene, 1-hexene terpolymer was produced underconditions described in Example 18. A terpolymer with MI 0.4, R_(d) 5.6and density 0.924 was produced.

                                      TABLE I                                     __________________________________________________________________________    CATALYST REACTIVITY AND PRODUCTIVITY                                          Support.sup.a                                                                          mmoles/g support     Cocat-   Partial.sup.d                                                                           Reac-                                                                             Produc-                  Exam-                                                                             Calcin-                                                                            Si.sup.g                                                                          Mg      Reac-                                                                             Reactor.sup.b                                                                      alyst.sup.c                                                                            Pressure  tivity                                                                            tivity                                                                             Resin               ple ation                                                                              Com-                                                                              Com-    tor Pressure                                                                           mmoles/                                                                            Wt. %                                                                             psig mol %                                                                              g/g g/g  Density             #   T, °F.                                                                      pound                                                                             pound                                                                             TiCl.sub.4                                                                        T, °F.                                                                     psig g catalyst                                                                         C.sub.2 H.sub.4                                                                   H.sub.2                                                                            C.sub.4 H.sub.8 --1                                                                cat/hr                                                                            catalyst                                                                           g/cc                __________________________________________________________________________    1   392  none                                                                              0.5 3.0 221 550  9.2  --  50   --   2445                                                                              2,455                                                                              --                  2   572  1.23                                                                              1.37                                                                              1.26                                                                              215 550  8.5  --  50   --   3893                                                                              3,893                                                                              --                  3   none.sup.e                                                                         0.4.sup.f                                                                         1.25                                                                              1.25                                                                              215 550  8.5  --  50   --   2464                                                                              2,464                                                                              --                  4   572  0.7 1.9 1.8 160 350  8.5  --  50   22   4797                                                                              4,797                                                                              0.922               5   none.sup.e                                                                         0.4.sup.f                                                                         1.25                                                                              1.25                                                                              160 350  8.5  --  50   22   5763                                                                              5,763                                                                              0.916               6   700  0.5 1.25                                                                              1.25                                                                              168 600  3.7  4   0.22.sup.h                                                                         13.3 --  16,500                                                                             0.924               __________________________________________________________________________     .sup.a Davison Grade 952 silica                                               .sup.b Polymerization of ethylene under particle form slurry conditions i     isobutane at indicated total pressure with ethylene                           .sup.c Triisobutylaluminum                                                    .sup.d Partial pressure of hydrogen in psig                                   .sup.e Davison Grade 952 silica completely reacted with                       hexamethyldisilazane and dried at 110° C. in N.sub.2 for one hour      .sup.f 7 wt. % excess hexamethyldisilazane                                    .sup.g Hexamethyldisilazane                                                   .sup.h Mol %                                                             

                                      TABLE II                                    __________________________________________________________________________    VARATIONS IN CATALYST PREPARATION                                             Support.sup.a                                                                          mmoles/g support     Cocat-    Partial.sup.d                                                                      Reac-                            Exam-                                                                             Calcin-                                                                            Si.sup.i                                                                          Mg      Reac-                                                                             Reactor.sup.b                                                                      alyst.sup.c                                                                             Pressure                                                                           tivity       Resin               ple ation                                                                              Com-                                                                              Com-    tor Pressure                                                                           mmoles/                                                                            Wt. %                                                                              psig g/g          Density             #   T, °F.                                                                      pound                                                                             pound                                                                             TiCl.sub.4                                                                        T, °F.                                                                     psig g catalyst                                                                         C.sub.6 H.sub.12 --1                                                               H.sub.2                                                                            cat/hr                                                                            MI.sup.e                                                                         HLMI/MI.sup.f                                                                       g/cc                __________________________________________________________________________    7   400  0.62                                                                              1.36                                                                              1.26                                                                              215 550  8.5  --   50   2156                                                                              0.5                                                                              29.6  --                  8   400  1.22                                                                              1.31                                                                              1.24                                                                              215 550  8.5  --   50   2266                                                                              0.6                                                                              24.3  --                  9   400  1.83                                                                              1.36                                                                              1.24                                                                              215 550  8.5  --   50   1002                                                                              0.5                                                                              26.2  --                  10  400  2.47                                                                              1.36                                                                              1.25                                                                              215 550  8.5  --   50   1052                                                                              2  21.8  --                  11  none.sup.g                                                                         0.4.sup.h                                                                         1.25                                                                              1.25                                                                              215 550  8.5  --   50   2464                                                                              1.3                                                                              28.7  --                  12  none.sup.g                                                                         1.25                                                                              1.25                                                                              1.25                                                                              220 550  5.0       0.08.sup.l                                                                          581                                                                              -- --    --                  13  none.sup.g                                                                         1.9.sup.j                                                                         1.9 1.9 130 265  8.5  40   50   2508                                                                              4.7                                                                              32.0  0.930               14  none.sup.g                                                                         0.9.sup.k                                                                         1.8 1.9 130 265  8.5  40   50   2519                                                                              2.9                                                                              29.4  0.930               15  none.sup.g                                                                         none                                                                              1.9 1.9 130 265  8.5  40   50   2405                                                                              1.0                                                                              60.5  0.930               __________________________________________________________________________     .sup.a Davison Grade 952 silica                                               .sup.b Polymerization of ethylene under particle form slurry conditions i     isobutane at indicated total pressure with ethylene                           .sup.c Triisobutylaluminum                                                    .sup.d Particle pressure of hydrogen in psig                                  .sup.e Melt index method: ASTM D 123862 condition E                           .sup.f High load melt index method: ASTM D 123862 condition F                 .sup.g Davison Grade 952 silica completely treated with                       hexamethyldisilazane and dried at 110° C. in N.sub.2 for one hour      .sup.h 7 wt. % excess hexamethyldisilazane                                    .sup.i Hexamethyldisilazane                                                   .sup.j 23 wt. % excess hexamethyldisilazane                                   .sup.k 13 wt. % excess haxamethyldisilazane                                   .sup.l Mol %                                                             

                                      TABLE III                                   __________________________________________________________________________    CATALYST EVALUATION UNDER PARTICLE                                            FORM POLYMERIZATION CONDITIONS                                                __________________________________________________________________________    Support.sup.a                                                                            mmole/g support      Reactor                                                                            Cocatalyst.sup.d                         Example                                                                            Calcination                                                                         Si.sup.b                                                                            Mg.sup.c  Reactor                                                                            Pressure                                                                           mmoles/                                  #    T, °F.                                                                       Compound                                                                            Compound                                                                            TiCl.sub.4                                                                        T, °F.                                                                      psig g support                                __________________________________________________________________________    16   none.sup.i                                                                          none  1.25  1.25                                                                              168  600  0.9                                      17   1100  0.55  1.25  1.25                                                                              169  600  3.7                                      18   none.sup.i                                                                          1.75  2.50  2.50                                                                              155  600  2.0                                      19   none.sup.i                                                                          1.25  1.25  1.25                                                                              165  600  3.0                                      __________________________________________________________________________                                            MD.sup.h                              Example                                                                            Wt. %                                                                             Mol %         Productivity     Tear                                  #    C.sub.2 H.sub.4                                                                   H.sub.2                                                                          C.sub.4 H.sub.6 --1                                                                 C.sub.6 H.sub.12 --1                                                               g/g catalyst                                                                         R.sub.d.sup.e                                                                     MI.sup.f                                                                         ρ.sup.g                                                                      g                                     __________________________________________________________________________    16   4   0.2                                                                              12    --    8,300 3.7 0.8                                                                              0.920                                                                            130                                   17   3.5 0.3                                                                              14    --   12,500 2.9 0.7                                                                              0.919                                                                            274                                   18   4   0.2                                                                              1.8   2.4    130  3.1 1.0                                                                              0.918                                                                            --                                    19   4   0.04                                                                             9.8   2.6  22,000 5.6 0.4                                                                              0.924                                                                            --                                    __________________________________________________________________________     .sup.a Davison Grade 952 silica                                               .sup.b Hexamethyldisilazane                                                   .sup.c Din-butylmagnesium (7.5)/triethylaluminum                              .sup.d Triisobutylaluminum                                                    .sup.e Polymer Engineering and Science, Vol. II, p. 124-128 (1971)            .sup.f Melt index method: ASTM D 123862 condition E                           .sup.g Density, g/cc                                                          .sup.h Notched Elmendorf machine direction tear method: ASTM D1922            .sup.i Davison Grade 952 silica completely reacted with                       hexamethyldisilizane and dried at 110° C. in N.sub.2 for one hour 

We claim:
 1. A solid catalyst for use with an organometallic cocatalystin the polymerization and copolymerization of 1-olefins prepared by themethod comprising the steps of:(A) reacting a support comprising(1)silica, alumina, silica-alumina or mixtures of these having surfacehydroxyl groups and dried or calcined at a temperature of at least about200° C., or (2) silica, alumina, silica-alumina or mixtures of thesehaving surface hydroxyl groups and reacted with an organosilane which isreactive with said groups followed by removal of any excess of saidorganosilane and reaction by-products, with (B) an excess relative tosaid hydroxyl groups of an organosilicon compound which is reactive withsaid hydroxyl groups of the formula (R₃ Si)₂ NH, where R is ahydrocarbyl group selected from C₁ -C₂₀ alkyls, aryls, alkaryls,aralkyls or mixtures of these; and, (C) a Group IIA organometalliccompound or complex of said Group IIA compound with a Group IIIAorganometallic compound; followed by (D) a transition metal compound ofa Group IVB, Group VB or mixtures of these metals; wherein said excessorganosilicon compound of (B) is not removed prior to the addition ofsaid transition metal compound of (D).
 2. The catalyst of claim 1wherein an inert liquid medium is present during said reaction.
 3. Thecatalyst of claim 2 wherein said inert liquid comprises a liquid alkane.4. The catalyst of claim 1 wherein said support is dried or calcined ata temperature from about 200° C. to about 1000° C. by heating.
 5. Thecatalyst of claim 1 wherein said transition metal of 1(D) comprisestitanium.
 6. The catalyst of claim 1 wherein the amount of saidtransition metal compound of 1(D) is from 5-200 wt. % of the equivalentamount of said surface hydroxyl groups of 1(A).
 7. The catalyst of claim1 in combination with an organometallic cocatalyst wherein the ratio ofthe amount of metal in said cocatalyst to the amount of said transitionmetal of 1(D) is up to about 500 to
 1. 8. The catalyst of claim 1wherein said organosilane compound of 1(A-2) comprises one or more ofsaid following compounds:

    (R.sub.3 Si).sub.2 NH

    R.sub.n SiX.sub.4-n

where n is 1, 2 or 3, X is group chemically reactive with the hydroxylgroups of the silica or alumina, and R is hydrogen and/or hydrocarbyl.9. The catalyst of claim 1 wherein said metal of Group IIA comprisesmagnesium.
 10. The catalyst of claim 9 wherein said magnesium compoundis of the formula MgR₂.nAlR₃ wherein R is a hydrocarbyl group andn=about 0-2.
 11. The catalyst of claim 1 wherein said organometalliccompound of 1(C) has a molar ratio to the hydroxyl groups of 1(A) ofabout 0.1-5.
 12. The catalyst of claim 1 wherein said transition metalcompounds of 1(D) comprise halides and alkoxy halides.
 13. The catalystof claim 12 wherein said metals comprise one or more of titanium,zirconium and vanadium.
 14. The catalyst of claim 1 wherein saidtransition metal compound of 1(D) is one or more of the formulas:

    TiX.sub.4

    TiX.sub.m (OR').sub.4-m

in which m is 1, 2 or 3, R' is selected from alkyl, aryl, cycloalkyl,alkaryl, cyclopentadienyl and alkenyl, each of these groups having 1 to12 carbon atoms, and X is halogen.
 15. The catalyst of claim 1 whereinthe support of (A) is reacted with the compound of (B), the resultingproduct is reacted with the compound or complex of (C), and the productthereof reacted with (D).
 16. The catalyst of claim 1 wherein a compoundof (B) is added to a support of (A-2) before or after mixing with acompound or complex of (C) and the resulting product reacted with acompound or mixture of (D).
 17. The method of making a solid catalystfor use with an organometallic cocatalyst in the polymerization andcopolymerization of 1-olefins, said method comprising the steps of:(A)reacting a support comprising(1) silica, alumina, silica-alumina ormixtures of these having surface hydroxyl groups and dried or calcinedat a temperature of at least about 200° C., or (2) silica, alumina,silica-alumina or mixtures of these having surface hydroxyl groups andreacted with an organosilane which is reactive with said groups followedby removal of any excess of said organosilane and reaction by-products,with (B) an excess relative to said hydroxyl groups of an organosiliconcompound which is reactive with said hydroxyl groups of the formula (R₃Si)₂ NH, where R is a hydrocarbyl group selected from C₁ -C₂₀ alkyls,aryls, alkaryls, aralkyls or mixtures of these; and, (C) a Group IIAorganometallic compound or complex of said Group IIA compound with aGroup IIIA organometallic compound; followed by (D) a transition metalcompound of a Group IVB, Group VB or mixtures of these metals; whereinsaid excess organosilicon compound of (B) is not removed prior to theaddition of said transition metal compound of (D).
 18. The method ofclaim 17 wherein an inert liquid medium is present during said reaction.19. The method of claim 18 wherein said inert liquid comprises a liquidalkane.
 20. The method of claim 17 wherein said support is dried orcalcined at a temperature from about 200° C. to about 1000° C. byheating.
 21. The method of claim 17 wherein said transition metal of20(D) comprises titanium.
 22. The method of claim 17 wherein the amountof said transition metal compound of 20(D) is from 5-200 wt. % of theequivalent amount of said surface hydroxyl groups of 20(A).
 23. Themethod of claim 17 wherein said organosilane compound of 20(A-2)comprises one or more of said following compounds:

    (R.sub.3 Si).sub.2 NH

    R.sub.n SiX.sub.4-n

where n is 1, 2 or 3, X is a group chemically reactive with the hydroxylgroups of the silica or alumina, and R is hydrogen and/or hydrocarbyl.24. The method of claim 17 wherein said metal of Group IIA comprisesmagnesium.
 25. The method of claim 24 wherein said magnesium compound isof the formula MgR₂.nAlR₃ wherein R is a hydrocarbyl group and n=about0-2.
 26. The method of claim 17 wherein said organometallic compound of20(C) has a molar ratio to the hydroxyl groups of 20(A) of about 0.1-5.27. The method of claim 17 wherein said transition metal compounds of20(D) comprise halides and alkoxy halides.
 28. The method of claim 27wherein said metals comprise one or more of titanium, zirconium andvanadium.
 29. The method of claim 17 wherein said transition metalcompound of 20(D) is one or more of the formulas:

    TiX.sub.4

    TiX.sub.m (OR').sub.(4-m)

in which, m is 1, 2, or 3, R' is selected from alkyl, aryl, cycloalkyl,alkaryl, cyclopentadienyl and alkenyl, each of these groups having 1 to12 carbon atoms, and X is halogen.
 30. The method of claim 17 whereinthe support of (A) is reacted with the compound of(B), the resultingproduct is reacted with the compound or complex of (C), and the productthereof reacted with (D).
 31. The method of claim 17 wherein a compoundof (B) is added to a support of (A-2) before or after mixing with acompound or complex of (C) and the resulting product reacted with acompound or mixture of (D).